Oil regulating means for sewing machines



M215? E9 1942 D. A. GRAEssER 2,283,869

OIL REGULATING MEANS FOR SEWING MACHINES l Filed Jan. 5, 1940 l wwwm riiIl hook. y

Patented May19, 19412 l i` l UNITED s'ra'risg PATENT OFFICE David A. Graesser, Elizabeth, N. J., assignor to f The Singer Manufacturing Company, Elizabeth, N. J.,acorporation of New Jersey f w Application Janary 5, 1.940, serial No. 312,467

6 Claims.

This invention relates-to sewing machines and more particularly to `means for supplyingl oil to the raceway of a rotary hook, and has for its objective the provision of improved means for regulating the flow of oil to the raceway of the The supply of oil to the raceway of a rotary hookmust be very accurately. controlled. Too much oil will soilgthe material being sewn and too little will cause the hook to heat and destroy the bearing surface ofthe raceway.v Heretofore means have been provided for regulating the flow of oil to the raceway of a hook. However, in these prior devices, lif the regulating means should become clogged, the oil supplyto the raceway of the hook ceases and the hook is quickly destroyed by friction and heat. It is one of the objects of my invention to overcome this diniculty. Y

With the above and other objects in viewas will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawing of a preferred embodiment of the invention, from which the several features yof the invention and the advantages attained thereby will be readily understood by those skilled in the art.

Figure 1 is alvertical section taken through vthe bed of a sewing machine embodying my invention, the operating parts below the bed being shown in full lines.

Figure 2 is a sectional view taken along the line 2-.2 of Figure 3.

Figure 3` is an end elevation,

right of Figure 2.

Figure 4 is a fragmentary detail view. Figure 5 is a view` similar to Figure 2, of a looking from the v*modified form of my improved device.

In the embodiment of this invention selected (CL i12-256) by the bed. Fixed to the end of the shaft I'l.is a. rotary hook I8 which cooperatesy with, the usual reciprocatory needle I9 in the formation of lockstitches. l For a more detailed description of the sewing machine oil-pan and oil-pump reference may bek had to Patent No. 2,206,285 dated July 2, 1940, issued toR. Kaier for a Sewing machine.

As more clearly shown` in Figs. 2 and 5, the bearing bushing 28 ls formed with a conduit 22 which is connected with the centrifugal pump I3 by the tube 23 so thatwhen thel machine is op-v erating oil is supplied from the reservoir A by thecentrifugal pump I3 through the tube23 and rto the `conduit 22 under pressure. Conduit 22 and connects thelcircular groove 24 with. asec4 ond circular groove 28 which is formed slightly eccentric relative to the shaft Il Vso that its outer y periphery will connect with the conduit 26`but :for illustration, I0 represents the bed-plate of a machineformed with depending side and end walls which rest u pon the gasket of resilient material II carried by the oil-pan I2. The bed of the sewing machine together with the oil-pan form an oil-tight compartment which houses the actuating mechanism of the machine.

Carried by the bed Ill of the machine is a centrifugal pump I3, actuated by the usual vertical shaft I4 which has its upper 4end operatively connected to the needle-baractuating shaft (not shown). The shaft I4 through the gears I5 and I6 actuate the hook-shaft I1 which is journaled in the bearing bushings 20, 2l carried will not connect with the conduit 22.

The shaft I'l is formed with a .longitudinal arranged bore'38`and a radial duct 3I which communicates with the' circular groove 28 in the bearing bushing 28. The'end of the hook-shaft Il, to which the hook I8 is fixed is provided with a screw 32 which closesthe open end of the 1ongitudinal bore 30 in the shaft I'I. Carried by the u screw` and extending into the bore` 30 is alter cartridge 34 for llteringoil passing through it and the cartridge, may be readily removed, cleaned, Vand replaced or if desired a new filter may be substituted for the old one.

The screw 32 isformed with a'radial duct 36 which leads the oil, that passes through the filter' I 34, to a circular chamber 3l formed between the screw 32 vand the hook-shaft. The oil is led from thechamber 31 through Ia radial duct 38 and circumferential groove 38 in the shaft Il tothe conduits 39 formed in the body of the hook I8. These conduits 39 are disposed substantially apart and the outer ends are connected with the raceway 40 yformed in the hookbody by the grooves 4I. Journaled in the race- Way 48 in the hook-body is the bearing rib 42 of the usualistationary thread-case 43. It will be understood that the thread-case is formed with an ear 44 which cooperates with a thread-case restraining finger xed to a stationary part of the machine, for the purpose of preventing the thread-case from turning with the rotary hook.

The pump and conduits are designed to supply an excess of oil to the conduit 26 so that if the open end of the conduit 26 kis completely closed an excess of oil will be supplied to the raceway of the hook, and if the end of the conduit 26 is wide open `no oil will be supplied to the hook. In order to regulate the fiow of oil to the hook, I have provided a disk 44 which is fitted on the end of the bushing 20 which extends intoA the reservoir. The disk 44 is formed with an elongated slot 45 through which the oil supply tube 23 extends. The disk 44 is also formed with a second elongated slot 46 which receives the` shouldered screw 41 threadedinto the bushing 20, this slot being adapted to overlie the end of the conduit 26. Between the head of the screw 41 and the disk 44 there is interposed afiat spring 48 which resiliently urges the disk against the bushing and frictionally holds it in adjusted position. To adjust the flow of oil to the `hook raceway, it is only necessary to grasp the fingerpiece 49 `and shift the 'disk in the direction desired. It will, of course, be understood that one end of the slot 46 is so arranged that shifting of the disk in a clockwise direction as viewed in Figure 3 will close'the end of the conduit26 and shifting the disk 44 in `a. counterclockwise direction will open the conduit. l

In Figure 5 -I have shown a modification of my improved oil regulating device. In this modification a plug 50 is screwed into the open end of the conduit 26. The plug 50 is formed with a centrally arranged longitudinal bore 5| and radial ports 52. A screw 53 having a tapered end is threaded into the longitudinal bore of the plug 5U so that itV may be adjusted longitudinally to regulate the iiow of oil outof the ports 62, and a lock-nut 55 is provided for the purpose of locking the screw 573 in its adjusted position.

-From the Vabove it for any Yreason the reduced openingsl to the ports 52, or the reduced opening shown in Figure 3,

become clogged the pressure of the oil in the conduit 26 will increase and the oil will be supplied to the hook in too large a quantity. 'When this is noticed by the operator it will onlyr be necessary to shift the disk 44, or back out the screw 53 and clean the openings. l

From the foregoing description it will be obvious that the elements employed and details of construction are suspectible of material varia- -tions. The privilege is therefore reserved of resorting to all such legitimate changes therein as may be fairly embodied within the spirit and scope of the appended claims.

Having thus set forth the nature of the invention, what I claim herein is: l

1. A sewing machine having in combination, a rotatable hook-shaft formed with a longitudinal bore, a hook carried by said shaft and having a raceway in which a thread-case is journaled, oil conducting means for conducting oil from the bore of said shaft to the raceway in said hook, a conduit for supplying oil to the bore in said shaft, an oil reservoir, means for supplying oil under pressure from said reservoir to said conduit,'and adjustable means connected with said conduit for allowing some of the oil in the conduit to return to said reservoir.

will be understood that if in said shaft,'a bushing in which the hook-shaft is journaled, said bushing being formed with a conduit which communicates with the bore in said shaft, means for supplying oil under pressure to said conduit, and means associated with said conduit for regulating the pressure of the oil therein.`

3. A sewing machine having in combination, arotatablehook-shaft formed with a longitudinal bore, a hook carried by said shaft and having a raceway in which a thread-case is journaled, oil conducting means for conducting oil from the bore of said shaft to the raceway in said hook, a conduit for supplying oil to thebore in said shaft, a bushing in which said hook-shaft is journaled, said bushing being formed with a conduit which communicates with the bore in the hook-shaft, an oil reservoir below the level of said shaft, a pump for supplying oil under pressure from said `reservoir to the conduit, means for returning some of the oil supplied to said conduit to said reservoir and means for regulating the amount of oil returned to the reservoir.

4. A sewing machine having'in combination, a rotatable hook-shaft formed with a longitudinal bore, a hookcarri'ed bysaid shaft and having a` raceway inwhich a thread-cassis journaled, oil-conducting means for conducting oil from the bore of said shaft to the raceway `in said hook, a conduit for supplying oil to the bore in said shaft, a bushing in which said hook-shaft is journaled, said bushing being formed with a conduit which communicates with the bore in the hook-shaman oil reservoir below the level of said shaft, a pump for supplying oil under pressure from said reservoir to the conduit, means for returning some of the oil supplied to said conduit to said reservoir and manually controlled meansl for regulating the amount of oil returned to the reservoir.

5. A sewing machine having in combination, a rotary hook `provided with a bearing raceway,

an oil reservoir, a conduit leading to the raceway in said hook, a pump for supplying oil under pressure from said reservoir to said conduit, means for conducting some of the oil in said conduit backto the reservoir, and adjustable means for regulatingthe amount of oil returned to the reservoir.

6. A sewing machine having in combination, a hook-shaft provided with a longitudinal bore, a hook secured to said shaft 'and provided with a raceway which communicates with the bore in said shaft, a radially arranged duct leading to the bore in said shaft,a filter located in the bore of said shaft, a bushing provided with a conduit which communicates with the radial duct in the shaft, a reservoir located below said bushing, means for supplying oil from the reservoir to the conduit in the bushing under pressure, and an adjustable valve located in the conduit i'n said bushing for regulating the pressure of the oil in said conduit.

DAVID A. GRAESSER. 

